diff --git a/AdaptiveBrightness/main.cpp b/AdaptiveBrightness/main.cpp
index 37bd397..88e4ded 100644
--- a/AdaptiveBrightness/main.cpp
+++ b/AdaptiveBrightness/main.cpp
@@ -17,16 +17,21 @@ int main(int argc, char* argv[])
 
     SensorDriver sensorDriver;
 
-    const auto sensors = sensorDriver.enumerateSensors();
+    auto sensors = sensorDriver.enumerateSensors();
 
-    for(const auto& sensor: sensors) {
-        const auto sensorRange = sensor.readRange();
-        const auto sensorValues = sensor.readValues();
+    for(auto& sensor: sensors) {
+        if(sensor) {
+            const auto sensorRange = sensor.readRange();
+            const auto sensorValues = sensor.readValues();
 
-        qInfo(ltr("Sensor range: [%1,%2]").arg(sensorRange.first).arg(sensorRange.second));
+            qInfo(ltr("Sensor range: [%1,%2]").arg(sensorRange.first).arg(sensorRange.second));
 
-        for(size_t i = 0; i < sensorValues.size(); ++i) {
-            qInfo(ltr("Sensor value %1: %2").arg(i).arg(sensorValues[i]));
+            for(size_t i = 0; i < sensorValues.size(); ++i) {
+                qInfo(ltr("Sensor value %1: %2").arg(i).arg(sensorValues[i]));
+            }
+        }
+        else {
+            qWarning(ltr("Sensor is invalid"));
         }
     }
 
diff --git a/AdaptiveBrightness/sensor_driver.cpp b/AdaptiveBrightness/sensor_driver.cpp
index 89aa3e0..d534bcb 100644
--- a/AdaptiveBrightness/sensor_driver.cpp
+++ b/AdaptiveBrightness/sensor_driver.cpp
@@ -14,7 +14,7 @@ SensorDriver::Sensor::~Sensor()
     qDebug(ltr("Destroying sensor on serial port %1").arg(m_serialPortName));
 }
 
-std::pair<int, int> SensorDriver::Sensor::readRange() const
+std::pair<int, int> SensorDriver::Sensor::readRange()
 {
     qDebug(ltr("Reading range of sensor on port %1").arg(m_serialPortName));
 
@@ -26,7 +26,7 @@ std::pair<int, int> SensorDriver::Sensor::readRange() const
     return parseRangeResponse(response);
 }
 
-std::vector<int> SensorDriver::Sensor::readValues() const
+std::vector<int> SensorDriver::Sensor::readValues()
 {
     qDebug(ltr("Reading values of sensor on port %1").arg(m_serialPortName));
 
@@ -43,7 +43,7 @@ SensorDriver::Sensor::Sensor(const QString& serialPortName) : m_serialPortName(s
     qInfo(ltr("Creating sensor on serial port %1").arg(m_serialPortName));
 }
 
-bool SensorDriver::Sensor::isValidSensor() const
+bool SensorDriver::Sensor::isValidSensor()
 {
     const auto versionCmd = QByteArray(VERSION_CMD.data(), static_cast<int>(VERSION_CMD.size()));
 
@@ -60,12 +60,14 @@ bool SensorDriver::Sensor::isValidSensor() const
     return version == "AdaptiveBrightness v1.2";
 }
 
-bool SensorDriver::Sensor::getSensorCommandResponse(const QString& serialPortName, QByteArray command, QByteArray& response) const
+bool SensorDriver::Sensor::getSensorCommandResponse(const QString& serialPortName, QByteArray command, QByteArray& response)
 {
     QSerialPort serialPort;
     serialPort.setPortName(serialPortName);
     serialPort.setBaudRate(115200); // Not required, STM32 VCP works with any baud rate
 
+    m_errorOccurred = true; // Cleared on success
+
     if(!serialPort.open(QIODevice::ReadWrite)) {
         qCritical(ltr("Unable to open serial port %1, error code: %2").arg(serialPortName).arg(serialPort.errorString()));
         return false;
@@ -110,6 +112,7 @@ bool SensorDriver::Sensor::getSensorCommandResponse(const QString& serialPortNam
         return false;
     }
 
+    m_errorOccurred = false;
     return true;
 }
 
diff --git a/AdaptiveBrightness/sensor_driver.hpp b/AdaptiveBrightness/sensor_driver.hpp
index 7eda2b5..b946692 100644
--- a/AdaptiveBrightness/sensor_driver.hpp
+++ b/AdaptiveBrightness/sensor_driver.hpp
@@ -12,8 +12,10 @@ class SensorDriver {
       public:
         ~Sensor();
 
-        std::pair<int, int> readRange() const;
-        std::vector<int> readValues() const;
+        std::pair<int, int> readRange();
+        std::vector<int> readValues();
+
+        operator bool() const { return !m_errorOccurred; }
 
       private:
         friend SensorDriver;
@@ -25,10 +27,11 @@ class SensorDriver {
         static constexpr auto READ_CMD = std::string_view{"read csv"};
 
         const QString m_serialPortName;
+        bool m_errorOccurred = false;
 
-        bool isValidSensor() const;
+        bool isValidSensor();
 
-        bool getSensorCommandResponse(const QString& serialPortName, QByteArray command, QByteArray& response) const;
+        bool getSensorCommandResponse(const QString& serialPortName, QByteArray command, QByteArray& response);
 
         std::string parseVersionResponse(const QByteArray& response) const;
         std::pair<int, int> parseRangeResponse(const QByteArray& response) const;